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<h1><a name="SECTION0021700000000000000000">
19.7 <tt class="module">colorsys</tt> --
         Conversions between color systems</a>
</h1>

<p>
<a name="module-colorsys"></a>

<p>
The <tt class="module">colorsys</tt> module defines bidirectional conversions of
color values between colors expressed in the RGB (Red Green Blue)
color space used in computer monitors and three other coordinate
systems: YIQ, HLS (Hue Lightness Saturation) and HSV (Hue Saturation
Value).  Coordinates in all of these color spaces are floating point
values.  In the YIQ space, the Y coordinate is between 0 and 1, but
the I and Q coordinates can be positive or negative.  In all other
spaces, the coordinates are all between 0 and 1.

<p>
More information about color spaces can be found at 
<a class="url" href="http://www.poynton.com/ColorFAQ.html">http://www.poynton.com/ColorFAQ.html</a>.

<p>
The <tt class="module">colorsys</tt> module defines the following functions:

<p>
<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
  <td><nobr><b><tt id='l2h-4644' xml:id='l2h-4644' class="function">rgb_to_yiq</tt></b>(</nobr></td>
  <td><var>r, g, b</var>)</td></tr></table></dt>
<dd>
Convert the color from RGB coordinates to YIQ coordinates.
</dl>

<p>
<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
  <td><nobr><b><tt id='l2h-4645' xml:id='l2h-4645' class="function">yiq_to_rgb</tt></b>(</nobr></td>
  <td><var>y, i, q</var>)</td></tr></table></dt>
<dd>
Convert the color from YIQ coordinates to RGB coordinates.
</dl>

<p>
<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
  <td><nobr><b><tt id='l2h-4646' xml:id='l2h-4646' class="function">rgb_to_hls</tt></b>(</nobr></td>
  <td><var>r, g, b</var>)</td></tr></table></dt>
<dd>
Convert the color from RGB coordinates to HLS coordinates.
</dl>

<p>
<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
  <td><nobr><b><tt id='l2h-4647' xml:id='l2h-4647' class="function">hls_to_rgb</tt></b>(</nobr></td>
  <td><var>h, l, s</var>)</td></tr></table></dt>
<dd>
Convert the color from HLS coordinates to RGB coordinates.
</dl>

<p>
<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
  <td><nobr><b><tt id='l2h-4648' xml:id='l2h-4648' class="function">rgb_to_hsv</tt></b>(</nobr></td>
  <td><var>r, g, b</var>)</td></tr></table></dt>
<dd>
Convert the color from RGB coordinates to HSV coordinates.
</dl>

<p>
<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
  <td><nobr><b><tt id='l2h-4649' xml:id='l2h-4649' class="function">hsv_to_rgb</tt></b>(</nobr></td>
  <td><var>h, s, v</var>)</td></tr></table></dt>
<dd>
Convert the color from HSV coordinates to RGB coordinates.
</dl>

<p>
Example:

<p>
<div class="verbatim"><pre>
&gt;&gt;&gt; import colorsys
&gt;&gt;&gt; colorsys.rgb_to_hsv(.3, .4, .2)
(0.25, 0.5, 0.4)
&gt;&gt;&gt; colorsys.hsv_to_rgb(0.25, 0.5, 0.4)
(0.3, 0.4, 0.2)
</pre></div>

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